The construction and phenotypic analysis of genetically engineered mouse (GEM) strains are fundamental and integral for the study of pancreatic cancer, including the analysis of signaling molecules in this pathology, the discovery and analysis of novel genes and their linked networks, and the validation and assessment of novel therapeutic targets and associated molecular biomarkers. The Genetic Engineering Mouse Core (GEMC) of this PDAC POI will provide all the necessary expertise, reagents and services to generate four genetically engineered mouse (GEM) modeling projects per year of grant funding. The GEMC will work closely with POI project leaders, investigators to produce the most advanced cancer relevant GEM strains. Specifically: (A) Transgenics; the GEMC will support all aspects of the construction of transgenic mouse models, including advice, service, technologies and reagents for the optimal design and construction of each specific transgene. (B) Gene Targeting; We will support all aspects of the construction of knockout and knock-in mouse alleles, including provide services, support, advice, technologies and reagents for the optimal design, construction and production of each specific targeting vector and resulting mice. (C) Evaluate and implement new technologies for the construction of genetically engineered mice and derivative cells.